During the first charging process, the battery will lose some lithium due to formation of the solid electrolyte interface (Solid Electrolyte Interface, SEI), which may cause lithium loss of anode material, thereby reducing the battery capacity and the first time efficiency. The above phenomenon occurs particularly in the cathode plate which adopts alloy material (e.g. silicon alloy and tin alloy etc.) as the active substance. In addition, during the cyclic process of the Li-ion battery, the SEI is consumed and repaired, which leads to continuous decreasing of the battery capacity due to increasing of inactive lithium in the anode and cathode, resulting in reduction of battery cycle life. In order to avoid the reduction of battery capacity brought by irreversible capacity during first time charging-discharging and cyclic process of the battery, supplying some active lithium to the cathode electrode plate of the Li-ion battery can effectively solve the above problem.
In the related art, since the lithium piece of the battery is very thin and the strength is low, which cannot be manufactured continuously in practice due to strip breakage.